Oil gasifier



April 28, 1 64 s. H. BACKSTR'OM ETAL OIL GASIFIER Filed June 27, 1960 INVENTQRS SVEN HJALMAR BAG/(57770 M ATTORNEYS hottest zone of the gasifier.

United States Patent 3,131,037 ()IL GAFIER Sven l-lljaimar Backstrom and Erik Snne Bergliiv,

Boriange, weden, assigncrs to Stora Kopparbergs Bergslags Alttiebolag, Falun, Sweden, 21 company of Sweden Filed June 27, 196i), Ser. No. 39,132 Claims priority, application Sweden June 29, 1959 1 Claim. (Cl. 48-407) The gasification of oil serves to convert fuel oil into a combustible gas. Primarily, oil gasification is used in the producton of coal gas as well as of synthesis gases for chemical industrial purposes. In gasification, the oil is heated in any suitable manner to sufiiciently high temperatures to decompose the same into gaseous products and coke. It has also been found, however, that the use of an oil carburettor in direct connection with an industrial furnace will frequently give better results than a direct firing of the furnace with fuel oil through an oil burner. In an oil gasifier for this purpose the oil is most commonly heated by partial combustion. The hot, combustible gaseous mixture formed is then introduced directly into the furnace in which it is burnt together with secondary air which may be preheated. This will result in a flame of the same type as that obtained in usual gas firing practice and with the same possibilities of controlling the flame magnitude and intensity. In addition, oil splashing in the furnace is avoided, which could be harmful to the material being heat treated.

One prior-art oil gasifier comprises a cylindrical heating chamber having its axis extending vertically. The oil is supplied through nozzles mounted in the chamber wall onto the hot chamber bottom and is then gasified. Air is blown in towards the bottom through tangentially directed nozzles provided in the chamber wall so as to cause combustion of coke residues and to maintain the temperature at the chamber bottom. According to another prior embodiment, the axis of said oil gasifier is horizontal, and the oil is introduced at a central point so as to deposit onto the horizontal portion of the cylindrical wall, while the air is blown in tangentially to sweep the cylindrical heating chamber wall. However, in the prior-art constructions referred to it has not been possible to avoid a certain deposition of coke onto the internal wall surfaces of the gasifier, and, in addition, the air and oil nozzles were subjected to the maximum temperature within the gasifier and thus were subject to severe thermal and chemical attacking. Such attacking of the nozzles, of course, will reduce the possibility of maintaining the desired exact rates of flow of air and oil, and this will also increase the danger of an incomplete gasification operation.

The present invention, being especially directed to an oil gasifier adapted for direct connection to an industrial furnace, has for its object to dispose the oil and air nozzles in such a way that they will not be situated in the The purpose of this oil gasifier is to produce a highly efficient apparatus, which may operate either as a rotary or a stationary machine. The novel design of the apparatus was dictated by the indispensible requirements for solving the problem, i.e., to produce a combustible gas by a thorough mixing of the oil and air, in such ratio that portions of the oil will not burn with less air than desired, thereby resulting in the formation of coke, while other portions of the oil are burned with more air than desired, resulting in complete combustion, which obviously would not produce a combustible gas.

The oil gasifier according to the invention comprises a substantially cylindrical gasification chamber, means at one end of the gasification chamber for supplying oil and "ice air into the gasification chamber, and an outlet at the other end of the gasification chamber for discharging combustible gas formed in the gasification chamber, and the invention is characterized in that there is provided in said gasification chamber, at said one end thereof, a substantially cylindrical body, arranged to form an annular space with the wall of the gasification chamber, and that the supply nozzles for oil and air open tangentially in or near the bottom of this annular space.

Further objects of the invention will become obvious from the following description in conjunction with the accompanying drawing of an oil gasifier according to a preferred embodiment of the invention, and in which drawing:

FIG. 1 shows a longitudinal section through the oil gasifier;

FIG. 2 shows a perspective view of a portion of the gasifier according to FIG. 1, and

FIG. 3 is a perspective view corresponding to FIG. 2 and illustrating another embodiment.

Referring to FIG. Lnumeral 15 designates the gasification chamber which is suitably surrounded by a ceramic refractory lining 2 enclosed in a sheet-metal casing 1. Formed in one end wall is an outlet passageway 4 for the hot oil gas discharged. Mounted in the opposite end wall of the gasification chamber is a body 16, preferably of a ceramic material, which has a conical shape and which is provided with a projecting portion 13 which, similarly to the gasification chamber, is substantially cylindrical in shape thus forming an annular space 14 between said projecting portion and the gasification chamber wall. The bottom of this annular space is formed with four abrupt shoulders, see 19 in FIG. 2, and opening through these shoulders are the supply nozzles 8 for air and 9 for oil. In the embodiment shown, the oil nozzles are disposed within the air nozzles and are connected to an oil supply conduit 17 which is surrounded by an air supply conduit 18. Alternatively, of course, the oil nozzles may be separate from the air nozzles, it being understood, also, that the number of shoulders at the bottom of the annular space may be varied as desired. As a further alternative, the nozzles could discharge through a perfectly plane bottom surface.

The air and oil will be supplied tangentially into said annular space, and owing to the fact that the cross-sectional area of said space is smaller than that of the gasification chamber-being suitably less than half the crosssectional area of the gasification chamber-the rate of flow through the space 14 will be high, causing the oil and air to be intimately mixed before their arrival in the gasification chamber proper. The projecting portion 13 should be so formed that the annular space 14 will have a depth at least equal to, and preferably at least twice as large as, its width.

The nozzles 8 and 9 and the supply conduits 17 and 18 are embedded as a unit in the ceramic body 16 which is conically tapered to be readily inserted into, and removed from, the gasifier to facilitate inspection and replacement of the nozzles.

The supply pipes 17, 18 for air and oil, in the arrangement of the invention, can easily be centrally disposed whereby the gasifier may be made rotatable, for example by being assembled with a rotary furnace. In this case the supply pipes are connected to stationary oil and air conduits 7 and 6, respectively, through conventional sealing devices.

The variant of FIG. 3 distinguishes from the embodiment of FIG. 2 by the feature that the shoulders 20 through which the air and oil nozzles open, have been designed in a somewhat different way.

The risk of coke deposits on the walls of the gasification chamber has been found to be minimized by the arrangement according to the present invention. Further it is possible, as a measure of safety against any coke deposit, to provide two sets of nozzles, namely one set in which the nozzles are directed in one direction, and a second set in which the jets are directed in the reverse direction. When coke deposit has occurred the supply is switched over from one set of nozzles to the other whereby the coke deposit will be rapidly burnt away. Such a dual set of nozzles may easily be established by being embedded in a ceramic body, for instance of the kind illustrated in FIG. 1, which ensures simplicity of assembly and rapid replacement.

Further advantages of the arrangement according to the present invention reside in that the cylindrical projecting portion 13 provides satisfactory protection of the nozzles against radiation from the chamber Walls, and that the shape of the conical body 16 results in one single sealing surface which may be of importance where the oil gasifier is to operate at a certain overpressure, which condition is not unusual where the resistance to flow through the furnace is high.

What is claimed is:

In an oil gasifier wherein the gasification is etfected with the aid of partial combustion of the oil, so as to produce a combustible gas, saidgasifier including a substantially cylindrical gasification chamber, means including supply nozzles at one end of the gasification chamber for supplying oil and air into the gasification chamber, and an outlet at the other end of the gasification chamber for discharging combustible gas formed in said gasification chamber, at said one end of the gasification chamber a combined closure and supporting plug consisting of ceramic refracory material and having a substantially cylindrical body with a cylindrical reduced-diameter end portion of substantial length, the diameter and length of said cylindrical reduced-diameter end portion being such as to define, in cooperation with the wall of the gasification chamber, an annular space having a depth at least twice its Width and a cross-section at most equal to half the cross-sectional area of the cylindrical gasification chamber; said reduceddiameter end portion of said plug including a terminal cylindrical base portion concentric with said body and a plurality of abruptly inclined arcuate shoulder portions spaced about its base, said supply nozzles each comprising an annular slot-like air outlet surrounding and concentric With a central oil outlet and being disposed in said shoulder portions and opening into said annular space adjacent the bottom thereof tangentially with respect to said base portion; said plug containing separate oil and air channels for supplying oil and air to said outlets of said nozzles.

References Cited in the file of this patent UNITED STATES PATENTS 1,239,075 Bagnall et al Sept. 4, 1917 1,262,846 Rider Apr. 16, 1918 1,342,732 Anthony June 8, 1920 1,351,193 Southey Aug. 31, 1920 1,656,907 Bansen Ian. 24, 1928 1,795,037 Portail Mar. 3, 1931 2,628,674 Fore Feb. 17, 1953 2,777,407 Schindler Jan. 15, 1957 

